Sea change for shellfishermen

Friday

DENNIS — In the sandy parking lot outside the Aquacultural Research Corp. on Tuesday, a few dozen shellfishermen gathered to hear Eric Fisher, chief meteorologist for CBS Boston’s WBZ-TV News, speak on a topic that’s likely to have a profound effect on their industry: climate change.

“They’re farmers,” said Rick Sawyer, president of sales and marketing for the corporation, which supplies shellfish seed to about 80% of the Cape’s nearly 400 private aquaculture farms. “They depend on weather and they depend on temperature. Any change to that is a serious problem.”

Fisher began by reviewing long-term trends in global and regional weather patterns.

“Since the start of the industrial age, we’ve warmed a little more than 1 degree celsius for the planet, which doesn’t sound like a ton, but we get to 3, 4, 5 degrees and that’s a very different world than what we’re used to,” he said. “And already we’re starting to see some of those changes.”

More impressive than charts and graphs, Fisher said, is seeing the real-world effects of climate change on the local environment. He referenced the Gulf of Maine, which stretches north from Cape Cod to the southern tip of Nova Scotia, and is one of the fastest warming spots on the planet.

“In terms of all the global oceans, it’s warming faster than 99% of them,” Fisher said. “It just about touched 70 degrees last summer.”

The shifting temperature is already affecting the species that live in and migrate through North Atlantic waters, including lobsters, which were once prevalent in Mid-Atlantic waters off New Jersey and Maryland.

“That catch has been going north and north and north over time and now it's really moving in Maine and Nova Scotia,” Fisher said, “but around here lobsters don’t love temperatures above 68.”

According to Joshua Reitsma, a marine specialist with the Cape Cod Cooperative Extension and the state's representative to the East Coast Shellfish Growers Association, the link between climate change and growing challenges to the shellfishing industry is largely anecdotal. Reitsma said that to his knowledge, no scientific studies have been done to determine the cumulative effect that climate change could have on the industry.

“There’s so many factors with climate change, it’s beyond just temperature,” he said. “I think there’s people looking at certain aspects of it, but maybe not the whole picture together, just because it’s so complicated.”

Reitsma said that warming water temperatures have the potential to create major challenges for shellfishermen.

“When you have a changing environment, certainly it is the grounds for having new potential predators, parasites, diseases move in,” he said.

Among those predators are blue crabs, which are becoming more common on the southside of Cape Cod, and green crabs, which can problematic for shellfishermen in the Gulf of Maine when winters are mild.

An increase in the frequency of high precipitation events could also lead to more harvest closures and harmful algal blooms, according to Reitsma. Even blooms that don’t pose a hazard to humans can be dangerous for shellfish.

Paul Hamblin, who holds an aquaculture grant in Barnstable Harbor, is one of many farmers who have dealt firsthand with the effects of harmful algae.

“Just this past year I had problems with seed, and it was from an algae that came through and it just stopped growth on everything,” Hamblinhe said. “And it actually killed about 50% of my oysters.”

Warmer air and water temperatures can also create ideal conditions for vibrio bacteria, which causes illness in humans who eat infected shellfish.

“As you harvest from warmer waters, this bacteria can replicate pretty rapidly in oysters that are warm as opposed to oysters that are cold,” Reitsma said.

Even as temperatures rise, strict regulations imposed by the state have helped curb the rate of human illnesses caused by eating oysters infected by the bacteria, Reitsmahe said. But keeping the bacteria at bay can fall hard on shellfishermen.

“Farmers have had to gear up with coolers and ice machines and sometimes bigger boats or trucks,” he said.

To ease the burden of meeting food safety requirements, the state Department of Agricultural Resources offers grants that help shellfishermen purchasing the equipment, Reitsma said.

But even during the traditionally cold winter months, relative warm stretches can spell disaster for oysters, which go dormant when the temperature drops below about 40 degrees.

“We had a problem last year or the year before where we had a freeze, and the oysters were dormant,” Sawyer said, “and then the weather changed in early January and it got warmer, and they kind of woke up and started to want to eat, but there was no food in the water.”

A significant number of oysters at the corporation’s hatchery and at Cape aquaculture farms died as a result, Sawyer said.

“All these people, they lose their crops for the year,” he said. “Some people had a real serious problem.”

At his talk on Tuesday, Fisher explained that North Atlantic waters have historically cycled between warmer and cooler phases.

“We’ve been in that warm phase for several decades,” Fisher said. “As that starts to go back to a cooler phase, which should be happening in the next few years, I am very interested to see if that changes our surface temperatures here in New England, and if that tempers the warming that we’ve seen in recent years.”

Sea level rise is another potential problem. Globally, scientists have found that melting ice from Greenland and Antarctica is now contributing to sea level rise, Fisher said.

“Water warms up and it expands, just like air,” he said. “That alone is going to bring the sea level up, and when you start melting more of this ice, that’s a storage problem.”

For shellfishermen who access their grants while they’re exposed during low tide, rising waters pose a serious threat.

“The grants, we may lose them at some point in time because the sea level has risen to a point where they don’t go dry, and they can’t access them,” Sawyer said. “So it really affects what these people do.”

Hamblin, whose farm is currently dry at low tide, said he could likely adapt if his grant becomes permanently submerged, although doing so wouldn’t be easy.

“If sea level rises, now my farm won’t go dry at low tide anymore,” he said. “It’ll be a subtidal farm, which is a whole other ball game.”

The future for local shellfishermen isn’t entirely bleak. Following Fisher’s talk, Bonita Oehlke, who handles market development for the state Department of Agricultural Resources, spoke about the expanding market for U.S. shellfish exports.

The European Union, which has been closed to U.S. shellfish for about a decade, could potentially reopen as early as the spring, she said. Markets in China and Hong Kong also have a growing appetite for U.S. shellfish.

“U.S. products have a strong reputation for food safety, Oehlke said. “That’s especially true with the shellfish industry, which is one of the most regulated of all food products. ... We have so many interesting, high quality products with nuanced flavors.”

Sawyer said that whatever challenges lie ahead, the corporation and the Cape’s aquaculture farmers see the value in their work.

“If you were to talk to most of our employees, we realize that aquaculture is really a vital industry to the Cape economy,” he said. “We play a role in sustaining that, but we also play a role in maintaining a way of life that has been going on for generations, and we take a lot of pride in that.”

Follow Kristen Young on Twitter: @KristenCCT.

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